The long-term goals of this research are to 1) better understand the mechanisms by which cells, especially blood cells, differentiate from an immature to a functioning state, and 2) to determine the levels of control of differentiation which are altered in abnormally differentiated leukemic or other neoplastic cells. Cell Differentiation will be studies in developing granulocytes separated into fractions enriched with cells of varying degrees of maturity and in cells of acute and chronic leukemia. Changes in protein synthesis during development will be characterized, and transcriptional control will be documented by isolating messenger RNAs and studying their translation products in a cell-free system.